Imagine walking in only the x or only the y direction on a multivariable function f(x,y). The slope in these directions gives the idea of a partial derivative. It's much like the slope of a single variable function is the derivative, it is just now we have more than one direction we can go to. When heading, say, parallel to the x axis this is equivalent to saying the y is constant. This makes computing partial derivatives easy: just take a normal derivative as if the other variable is contant. Sorry for the bad audio quality on this one! **************************************************** YOUR TURN! Learning math requires more than just watching videos, so make sure you reflect, ask questions, and do lots of practice problems! **************************************************** ►Full Multivariable Calculus Playlist:    • Calculus III: Multivariable Calculus ...   **************************************************** Other Course Playlists: ►CALCULUS I:    • Calculus I (Limits, Derivative, Integ...   ► CALCULUS II:    • Calculus II (Integration Methods, Ser...   ►DISCRETE MATH:    • Discrete Math (Full Course: Sets, Log...   ►LINEAR ALGEBRA:    • Linear Algebra (Full Course)   *************************************************** ► Want to learn math effectively? Check out my "Learning Math" Series: https://www.youtube.com/watch?v=LPH2lqis3D0 ►Want some cool math? Check out my "Cool Math" Series:    • Cool Math Series   ***************************************************** ►Check out my 2nd Channel for lower production quality "live" math videos: https://www.youtube.com/channel/UCFNL8G1CZ4dH0p-Jf7UXqdQ ***************************************************** ►Follow me on Twitter: http://twitter.com/treforbazett ***************************************************** This video was created by Dr. Trefor Bazett BECOME A MEMBER: ►Join: null MATH BOOKS & MERCH I LOVE: ► My Amazon Affiliate Shop: https://www.amazon.com/shop/treforbazett